A display apparatus displays an image. A projector which is one of display apparatus projects an image onto a screen.
In order to display an image on a large screen, a plurality of projectors is necessary. U.S. patent application Ser. No. 11/948,927 discloses a plurality of projectors used to display an image on a large screen.
According to U.S. patent application Ser. No. 11/948,927, in order to form a large screen using several projectors, a camera is placed in front of the screen, images are projected onto the screen using the projectors at the back of the screen, and an overlapping area of two images is extracted using a phenomenon that the brightness of an overlapping area of several images increases, thereby controlling the locations of the projectors or the color of the image.
However, according to this method, it is difficult to detect the overlapping area of the projection images or it takes significant time to detect the overlapping area of the projection images. In addition, it is difficult to cope with change in locations of the projectors due to external shock or for different reasons.